水力压裂试验中煤体扰动应力变化规律研究  

Study on variation law of coal disturbance stress in hydraulic fracturing test

作　　者：陈凯 张东明[2,3] 任发科 CHEN Kai;ZHANG Dongming;REN Fake(Sichuan Work Safety Technology Center,Sichuan Administration of Work Safety,Chengdu 610045,China;State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;College of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]四川煤矿安全监察局安全技术中心,四川成都610045 [2]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [3]重庆大学资源与安全学院,重庆400044

出　　处：《煤矿安全》2023年第3期79-84,共6页Safety in Coal Mines

摘　　要：为探究煤层钻孔在水力压裂过程中,压裂钻孔周边煤层内的扰动应力变化规律;以筠连县金钟煤矿有限公司1703采煤工作面为试验地点,在确定相关水力压裂参数的基础之上,利用KSE-2-1型矿用本安数显钻孔应力计监测压裂过程中压裂钻孔周边不同距离煤层内的扰动应力变化情况。试验结果表明:水力压裂过程中出现煤体开裂现象时,其注水压力将会出现明显的下降,相应的其单位注水量将会出现一定的上升;水力压裂过程中,由压裂液所形成的扰动应力在煤层内的传递主要以衰减为主;同时,在水力压裂影响范围内,煤层内部的扰动应力变化主要包括3个阶段:原始应力阶段、应力响应阶段和应力趋稳阶段,并且处于应力响应阶段的煤层内部扰动应力值变化呈波浪式上升。In order to explore the variation of disturbance stress in the coal seam around the fracturing borehole in the process of hydraulic fracturing,taking the 1703 coal face of Junlian Jinzhong Coal Mine Company as the test site,on the basis of determining the relevant hydraulic fracturing parameters,KSE-2-1 mine intrinsic safety digital display borehole stress meter is used to monitor the variation of disturbance stress in coal seams at different distances around the fracturing borehole during fracturing.The field test results show that when coal cracking occurs in the process of hydraulic fracturing,the water injection pressure will decrease significantly,and the unit water injection will increase to a certain extent;in the process of hydraulic fracturing,the transmission of disturbance stress formed by fracturing fluid in coal seam is mainly attenuation;at the same time,within the influence range of hydraulic fracturing,the stress change in the coal seam mainly includes three stages:original stress stage,stress response stage and stress stabilization stage,and the change of disturbance stress in the coal seam in the stress response stage rises in a wave.

关 键 词：水力压裂 扰动应力 变化规律 注水压力 单位注水量 

分 类 号：TD712[矿业工程—矿井通风与安全]